With the continuous development of terminal technology, terminal devices have become more functional and provided users with better experiences, so people are increasingly using the terminal devices in various occasions. For example, people use the terminal devices to surf the Internet, watch videos, listen to music and the like while riding public transportations, and use the terminal devices to listen to music, record running information (running route, run duration) or the like while exercising or running.
As people increasingly use the terminal devices in various occasions, in particular to use the terminal devices in public places, the terminal devices become a target of larceny and robbery. For example, when a user listens to music with earphone plugged into the terminal device, the terminal device is generally placed in a pocket or a carry-on bag, which offers criminals an opportunity to take out the terminal device, unplug the earphone quickly and run away. Therefore, a method for protecting the terminal devices is required.